Useful and cost efficient fabrication of dot arrays for photonic crystals by direct write electron-beam lithography

An easy-to-use procedure for the generation of complex two-dimensional dot arrays for the application in Photonic Crystals is presented. In most cases dot array arrangements are designed in a high resolution manner which is a reaction to the demands for precise, uniform and reproducible shape of the dots. This leads to high data volumes and special requirements for the fabrication of this patterns by electron-beam lithography and in time consuming exposure procedures. The basic idea presented here is to define the dot elements of the designed patterns in the form of squares instead of circular shapes resulting in a crucial reduction of the data size. In some cases a coarse design grid can be applied resulting in a drastic reduction of processing time. We demonstrate that the use of rectangularly defined dots results in circular pattern shapes, caused by proximity effects, and has a positive influence on the process window.